响应曲面法优化TEMPO诱导氧化预处理工艺制备NFC

Optimization of TEMPO-Mediated Oxidation Pretreatment Process Using Response Surface Methodology

采用响应曲面法的Box-Behnken实验设计,考察TEMPO诱导氧化预处理工艺中,TEMPO、NaBr、NaClO的用量对氧化反应时间和氧化程度(NaOH的消耗量)的影响。研究结果表明:随着TEMPO和NaBr用量增加,氧化反应速率加快,反应时间缩短,氧化程度略有减小;随着NaClO的用量增加,氧化反应时间延长,氧化程度与之成线性增加趋势。通过Design-Expert软件在预设目标值的前提下,依据回归模拟方程优化得到了最佳的工艺条件:TEMPO用量0.024 mmol·g-1、NaBr用量2.50 mmol·g-1、NaClO用量7.13 mmol·g-1,在此条件下进行了验证实验,其反应时间为56.76 min,NaOH的消耗量为35.05 mL,与回归方程的预测值非常接近。在优化的工艺条件下,对纤维素进行了TEMPO氧化预处理,然后进行机械法研磨,最终制备得到了纳米纤化纤维素(NFC)。

The effects of the amount of TEMPO, NaBr and NaC10 in TEMPO-mediated oxidation pretreatment process on reaction time and oxidation degree （the consumption of NaOH） using response surface methodology were studied. The results showed that with the increased dosages of TEMPO and NaBr, the reaction time is reduced, the oxidation degree is slightly decreased; with the increased dosage of NaC10, the oxidation reaction time is extended, and the oxidation degree is linearly increased. By the Design-Expert software, on the premise of the preset target, the optimal pretreatment conditions was obtained according to regression simulation equation, the dosages of TEMPO, NaBr and NaC10 were 0.024 mmol·g-1, 2.50 mmol·g-1 and 7.13 mmol·g-1 respectively. A confirmatory experiment was conducted under the optimal process conditions, and the result is reaction time was 56.76 min, the consumption of NaOH was 35.05 mL. This result is very close to the predicted value. Finally, Nanofibrillated cellulose （NFC） was prepared by mechanical grinding the TEMPO-oxidation pretreatment cellulose under the optimized process conditions.